IEEE 2017-2018 Project Titles on Li-Fi
Abstract:The Internet of Things (IoT) can be used to help a variety of things connected to the network in home, building, factory, city, and so on. In the meantime, the Visible Light Communication (VLC) based on Light Emitting Diode (LED) has been focused as future communication facility. In this paper, we propose the IoT Device Management Protocol (IDMP) with VLC, named IDMP-VLC, which can be used to manage IoT devices in VLC networks. The IDMP-VLC protocol is a simple and self-configurable device management protocol. It provides device initialization and management operations, and data transmission operation. The IDMP-VLC will use IPv6 with IPv6 over Low power Wireless Personal Area Network (6LoWPAN). In the proposed scheme, the two different transmission schemes are used for communication between lighting device and IoT device: VLC for downstream from lighting to IoT device and WPAN (ZigBee or Bluetooth) for upstream from IoT device to lighting device. The proposed protocol is implemented and experimented with various devices on top of the Java Virtual Machine (JVM). From the experimentation, it is shown that the proposed IDMP-VLC can be effectively used for initialization, management, and data transmission with IoT devices over VLC networks.
Abstract:Recently, the visible light communication (VLC) is considered as a future emerging technology in the telecommunication and lighting industry, as defined in the IEEE 802.15.7 standard. In the meantime, the ANSI E1.45 standard was made to provide VLC data transmissions from a VLC data server to a lighting device that is equipped with a VLC transmitter in lighting control networks. However, the ANSI E1.45 scheme cannot provide reliable transmissions of VLC data, and thus a lost data, if any, cannot be recovered. To overcome such limitation, timer-based VLC data transmission schemes have been studied by applying the retransmission scheme of Internet. However, these schemes still have limitation that the lost VLC data cannot be recovered immediately. Hence, in this study, the authors propose new reliable transmission schemes for VLC data over lighting control networks. The proposed schemes are classified into the packet-based (PRVS) and fragment-based (FRVS) schemes. From performance analysis by simulation, the authors see that the FRVS gives the best transmission throughput among the four candidate schemes. In addition, it is shown that the proposed reliable transmission scheme can effectively perform the error recovery operation in the networks with packet losses, compared to the ANSI E1.45 scheme.
Abstract:A positioning system based on visible light communication (VLC) utilizes illuminating indoor lights to identify the location of objects. The complexity and the cost of VLC are largely affected by limited bandwidths on optical emitters and detectors. In this paper, we present an optical signaling and multiplexing technique, which employs Hadamard matrices to implement a multiple-input multiple-output (MIMO) system. Fundamental conditions to create nonnegative optical signals and brightness control are defined in conjunction with multiplexing different sources and receiving messages. By using two design methods n-1 and M constructions, Hadamard matrices can be used to implement MIMO VLC without considering bandwidth limits for emitters or receivers. Eventually, the presented model and the method generalize multiplexing techniques with orthogonality from a view of orthogonal matrices. Experiments show that the proposed positioning system has 0.02-m standard errors of identification due to the noise component in a slow optical receiver.
Abstract:We propose an indoor visible light communication (VLC) and positioning system using the orthogonal frequency division multiplexing access (OFDMA) scheme, which can provide both indoor positioning and communications. Three subcarriers with the maximum received signal intensity with respect to three light-emitting diodes (LEDs) are selected for indoor positioning based on the trilateration algorithm. The experiment results show that the proposed system with quadrature phase shift keying (QPSK) mapping offers a mean positioning error and an error vector magnitude of 1.68 cm and more than 15 dB, respectively.
Abstract:In this paper, we consider an outdoor visible light communications relaying system in which the relay node needs to transmit both its own information and the information from a source node simultaneously. A superimposed relaying (SR) strategy and the corresponding constellation design are presented. We derive the closed-form dominant term of average bit error rate (BER) for the system, and obtain an optimal power allocation to minimize the average BER. Simulation results demonstrate that SR can improve the error performance of the system significantly.
Abstract:In this paper, we investigate cooperative visible light communication (VLC) system where an intermediate light source acts as a relay terminal. We assume that relay terminal operates in full-duplex mode. In contrast to radio frequency counterparts, full-duplex VLC terminal is relatively easier to implement due to directive propagation characteristic of light. We first model VLC relay terminal taking into account loop interference channel based on ray tracing simulations. Then, we investigate error rate performance of the relay-assisted VLC system. Our performance evaluations demonstrate the superiority of full-duplex relaying over half-duplex counterpart especially for high modulation sizes.
Abstract:A novel indoor localization system is presented, where LED beacons are utilized to determine the position of the target sensor, including a camera, an inclinometer, and a magnetometer. The beacons, which can be a part of the existing lighting infrastructure, transmit their identifiers for long distances using visible light communication techniques. The sensor is able to sense and detect the high-frequency (flicker free) code by properly undersampling the transmitted signal. The localization is performed using novel geometric and consensus-based techniques, which tolerate well measurement inaccuracies and sporadic outliers. The performance of the system is analyzed using simulations and real measurements. According to large-scale tests in realistic environments, the accuracy of the proposed system is in the low decimeter range.
Abstract:The paper describes a microcontroller based secured optical wireless communication system using laser and phototransistor. These days the usage of Wi-Fi has reached to every nook and corner of the world. There are some downsides belong to the usage of Wi-Fi such as those concerning to the speed, limited bandwidth, security and range of its usage. In order to overcome these hitches we can use the advanced version of Li-Fi which is efficient, high speed, and fully networked wireless communication. If light contains encrypted message then both privacy and prevention from unwanted access along with high data rate can be achievable from Li-Fi. A new encryption technique based on substitution of ASCII value of characters implemented and reliable data transmission carried out. The proposed encryption algorithm primarily follows Caesar Cipher WHEEL substitution, acts similarly with Caesar wheel device by rotating circularly and changes the ASCII value of original message according to predefined values and length of repetition. Encryption of data, transmission, reception and conversion to original message are implemented successfully using laser, phototransistor, microcontroller and associated devices. Microcontroller performs as overall controlling and processing unit.